1. Field of the Invention
A pole climbing apparatus for use in the installation and repair of telephone lines and the like comprising an upper work platform and a lower climbing platform.
2. Description of the Prior Art
A number of tree or pole climbing devices are found in the prior art. For example, U.S. Pat. No. 3,856,111 shows a hand-climber-accessory for tree-climbing platforms for hunters and a horizontal base plate having a tree engaging blade. Angularly disposed frame members extend from the base plate to support a second blade or strap to engage the opposite side of the tree. The hand-climber accessory is positioned on the tree above the platform and includes parallel bars to engage the tree. Blades are attached to the bars to engage the tree. A hunter standing on the base plate alternately adjusts the elevation of the hand-climber accessory with respect to the base plate and raises or lowers the base plate by lifting and lowering his feet to first disengage and reengage the platform with respect to the tree at a different elevation.
An earlier patent U.S. Pat. No. 3,460,649 disclosed a similar climbing platform having a base plate positioned against the pole or tree. The operator places his arms around the pole or and pulls his feet upwardly to climb the pole or tree by raising the plate with respect to the pole or tree.
U.S. Pat. No. 3,955,645 discloses another hand-held climbing device in combination with a standing platform for climbing a tree by lifting his body with his feet in foot straps on the platform. This pivots the platform away from the tree so that the platform may be slipped up into a new position. When the platform is then pressed against the tree, it will be held in place so that the hand-held climbing device may then be pivoted upward to release and shimmied up the tree.
U.S. Pat. No. 3,485,320 illustrates a device for climbing a tree by this approximate method. The upper framework is shimmied up the tree against the force of a series of elastic vertical straps attached between the frame and a lower platform. The framework is then pivoted against the tree to lock it in place and the weight of the person is supported on the upper framework with the feet being raised so that the elastic straps may pivot the lower platform away from the tree to release it and raise it up the tree. When the person then places his weight again on the bottom platform, this pivots the platform against the tree to lock it in place whereby the upper framework may then be raised by the person's hands to release it from the tree and shimmy it further up. A series of these actions will raise the platform and the person up the tree to a selected position.
U.S. Pat. No. 3,419,108 discloses a portable tree stand engaging a tree and held in place by means of a series of spikes on the platform.
U.S. Pat. No. 2,392,538 and U.S. Pat. No. 2,842,300 show pivoting frameworks with a strap to engage a tree, the entire arrangement being moved upwardly by pivoting free from the tree and shimming up the tree under hand power.
The combination of hand-held pole grippers and foot operated pole grippers are shown in U.S. Pat. No. 213,715. Additional constructions for tree stand and climbing devices are shown in U.S. Pat. Nos. 758,200; 857,430; 1,106,098; 1,307,468; 2,174,525; 2,654,638; 3,237,720; 3,340,961; 3,606,315; 3,727,723; 3,944,022; and 4,008,785.
However none show a pair of working platforms using leg power to position the apparatus vertically on the pole or tree.